As is described in more detail hereinafter, a fuel valve is controlled by means of two variables: on the one hand a “peak duration” first variable which conditions a “peak current” first objective variable and on the other hand a “holding ratio” second variable which conditions a “holding current” second objective variable at the end of the holding phase.
The problem is that the relationship between a variable and the associated objective variable depends on numerous mechanical or electrical parameters that vary from one vehicle to another and can moreover vary as a function of temperature and/or time.
Direct open loop control therefore runs the risk of calculating a variable value that is too low with the risk of not producing the necessary objective variable. Thus if a peak current is too low there is a risk of the valve not opening or closing. On the other hand, if the peak current is too high, this leads to unnecessary wear of the valve.
In order to remedy these harmful differences and variations, the use of a servocontrol system may be envisaged, for example employing current regulation. The use of such a control system is very costly, however.
A low-cost solution is therefore looked for that makes it possible to circumvent these parameter differences and variations.